Electronic tuners for stringed musical instruments use some kind of pickup head to sense the sound vibrations corresponding to the note being played and convert that vibration to an electrical signal. Some tuners use microphones to pick up the tone from air-transmitted sound but such detection is susceptible to error or difficulty in tuning due to ambient noise also picked up by the microphone. The operation of such circuits involves first amplifying and filtering the signal, and then detecting it in a microprocessor to determine the fundamental frequency of the tone being detected utilizing a suitable tuning algorithm. In some circuits this frequency is compared with the true fundamental frequencies of the notes which are stored in processor memory. The frequency of the closest note to the detected frequency of the tone being detected is determined after which various outputs may be provided. Some outputs use a series of flashing lights in the form of light emitting diodes to indicate the closest note. U.S. Pat. No. 5,388,496 issued to Miller et al. discloses an additional output which indicates whether the frequency of the detected tone is above or below the frequency of the closest note. Other kinds of displays such as a null meter, an oscilloscope screen, or coloured lights have been used. U.S. Pat. No. 4,312,044 issued to Baba and U.S. Pat. No. 4,434,697 issued to Roses discloses use of a multi-digit segment display and an alphanumeric display, respectively.
The location of the electronics and display of known guitar tuners ranges from units which are contained in separate boxes as in U.S. Pat. No. 3,901,120 issued to Youngquist to a display in the form of a series of flashing lights on the edge of the guitar finger board as in Miller et al., supra. In Miller et al. the light display is connected by a cable to a casing mounted within the sound box of a guitar. For such an arrangement as in Miller, it would be necessary for a user to memorize which lights correspond to which notes as well as which colours indicate an out-of-tune tone being higher than the frequency of the note being played and which colours indicate an out-of-tune tone being lower than the frequency being played. It would also be necessary in Miller, supra., to connect the external cable from the casing within the sound box to the light display when it is desired to use the tuner.
Accordingly, it is an object of the invention to provide an improved tuner for a stringed musical instrument. It is a further object of the invention to provide a tuner for stringed musical instruments having an improved display. It is yet a further object to provide a tuner for stringed musical instruments implanted into the box and positionable so that it faces a user during tuning.